With the development of electronic digital technologies and digitization of consumer electronics, more and more digital electronic devices are emerging in families, for example, digitized entertainment devices such as a mobile phone or a camera, and household electrical appliances such as a personal computer or a digital television set. How to connect the digital electronic devices in a wired or wireless mode to constitute a local area network, for example, a home network, which can implement functions such as content sharing or mutual control, is a concept that the industry is conceiving and trying to realize. The digital electronic devices constituting the home network are called home network devices.
To facilitate interworking and control of different types of home network devices, a Uniform plug and play (UPnP, Uniform Plug and Play) technology is proposed in the prior art. UPnP is an architecture for global peer-to-peer (P2P, Peer-to-Peer) network connectivity of various digital electronic devices. In a UPnP system, a user controls a home network device through a control point (CP, Control Point) device in a home network; through the UPnP protocol and by invoking related control commands (actions) of the home network device supporting the UPnP technology (hereinafter referred to as a UPnP device), the control point device reads state information of the UPnP device in the home network and controls the UPnP device to perform corresponding operations.
To implement a scenario where multiple UPnP devices share media in the home network, UPnP defines an audio and video (AV, Audio and Video) standard; in the AV standard, three apparatuses are defined: a media server (MS, Media Server), a media-playing device (MR, Media Renderer), and a media control point (AV CP, Audio and Video Control Point). The media server is a device for storing media. The media renderer is a device for playing media. The AV CP is an apparatus for controlling the two devices. Through the AV CP, media resources of the media server may be browsed and the media of the media server may be played, which enables the media renderer to play the content in the media server. For example, as shown in FIG. 1a, if a user wants to watch a private video stored in a mobile phone or digital camera (namely, a media server) on a digital television set (namely, a media renderer), the AV CP obtains the content information of the private video from the mobile phone or digital camera, then generates a playlist (Playlist), and sends the playlist to the digital television set for storage, so that the digital television set obtains and plays the media resources (namely, videos) according to the playlist.
In the research and practice of the prior art, the inventor of the present invention finds that: the playlist that is generated by the media server or by the AV CP and sent to the media renderer is temporary; if the media server storing the content associated with the playlist is offline, or the Internet Protocol (IP, Internet Protocol) address changes, or the content itself changes, the playlist is partly or completely invalid, which affects the play experience of the user greatly.